Every other Row for a chart range

[Red Fish]

I need to chart out this sheet I have, but it has 51k rows. Too much to chart. So I am going to just do every other row. Right now I just hide every other row then select the two rows for my chart. This takes a while. I am thinking it would be better to just select every other row in the column and use that. I just don't know the syntax for it. Currently I use this to select.

Range("C:C,H:H").Select

How can I mod that to give me every other row in Column C and Column H?

Thanks

 

[Red Fish]

Any thoughts on this? I have a work around where I hide every other row using this code.

 Application.ScreenUpdating = False    Application.EnableEvents = False
     
    Dim Xi As Long
       For Xi = 2 To iRow Step 2
       Rows(Xi).Hidden = True
       
    Next Xi
    Application.ScreenUpdating = True
    Application.EnableEvents = True

But it takes quite awhile to hide all those rows. With a large number of files I need to process this will not work, just too slow. I have tried to do some loops to add all the cells I want in to a variable but that is not producing anything useful besides errors. I can't believe there is not a simpler solution. Although it is Microsoft.